Process of manufacture of wedge-shaped hollow bodies



Patented Dec. 9, 1930 UNITED STATES PATENT-OFFICE LUDWIG- STAIGER, F SPANDAU NEAR BERLIN, GERMANY, ASSIGNOR TO THE FIRM BOHRBACH METALL-FLUGZEUGBAU,

G. M. B. H., OF BERLIN, GERMANY PROCESS OF MANUFACTURE OF WEDGE-SHAPED HOLLOW BODIES Application filed. May 16, 1927, Serial No.

This invention relates to aircraft. The hitherto prevailing practice in aircraft rudder construction was to oin the trailing edges of the cover skins and then attach the. independently inzmufactured transverse re-inforcing members, finally riveting the'latter to the skins. These riveting opera-' tions are difficult and laborsome owing to the inconvenience of backing up the rivets inside the rudder body which is of comparatively small inside width.

Accordin to the present invention the manufacturing process -is simplified by the cover skin plates being first provided with the girders of the transverse re-inforcingmembers and, at certain continuous girders, with the transverse reinforcing web bars thereof, whereupon, the trailing edges of said plates having been interconnected, the free ends of the bars are joined to the corresponding other girders, and finally, the supporting body, the bearings, for instance, attached.

The accompanying drawings show, by Way of example, an embodiment of the present invention. v

Figs. 1- to 3 represent part of an aircraft rudder in plan view, side elevation and section.

Figs. 4 and 5"show two difierent stages of manufacture.

Fig. 6 is a detail.

Fig. 7 shows a section through a detachable wing trailing edge.

The aircraft rudder according to Figs. 1 to 6 includes a longitudinal Wall 1 forming the rudder base, transverse re-inforcing members 2, arranged vertically on their back wall, and top and bottom cover skin 3, 3 being connected with the girder members of thelongitudinal wall 1 and the transverse members 2 and joined at their trailing edge by means of an angle piece 5.

The rudder according to the present invention is assembled by riveting the approximately C-sectioned girders 6, 6 of the transverse members 2 on the inside of the top and bottom skin 3, 3 respectively, which riveting can be easily accomplished, as all plates are accessible from all sides (see Fig. 4). In ordinary practice the bars 7, 8, 9 forming the .13 in. the longitudinal walL. v 'tion of the hollowbody proper, the-supports small structural height of its trailing edge.

191,662, and in Germany May 18, 1926.

no inconvenience of backing up the rivets at the inside of the skin, as the plates allow of being spread apart considerably.

The skins are then brought to their correct diverging angle position and the bars 7, 8, 9 then joined to the upper girders 6, by driving a rive-t 11 vertical to the skin 3 through the free end of the bar 7, the riveting operation and backing up being effected Without hindrance owing to the favourable position. The free ends of the bars 8, 9 are then joined with each other and the girders 6, preferably by means of a rivet 12 driven parallel to the skin 3. The bar 9 at the same time serves as re-inforcement of the longitudinal wall 1, to which it is. attached by means of rivets backed up with the aid of tools easily passed through lightening holes After compleing members 4, being designed to form bear ings, are attached to same, which can be done without inconvenience owing to the rivets being easily accessible from all sides.

The above manufacturing process can be applied, in addition to air and water rudders for aircraft, to other wedge-shaped hollow bodies: it can, for instance, be used to produce the detachable low wing en-l piece represented in Fig. 7, which owing to the no considerably impedes assembly of web bars, girder members and stressed outer skin. According to the present invention such endpiece is bi-partite; its wedge-shaped trailing edge 14 is manufactured according to the. new method, whereas the advanced, more or less trapezoid sectioned supporting part 15 can be made in the course ofusual assembly owing to the rivets being relatively easily accessible. Both parts are joined at their base by connecting the converging web bars and by attaching small cover shackles 16.

It'is of no consequence for the nature of the invention. whether the webs of the transverse re-inforcing members 2 consist of more or less than three bars or whether the position of the rivets at the connection points differs from that indicated. in the drawing. Instead of one rivet one is free to use two 01' more rivets at the connection points. i

What I claim is:

1. An aircraft rudder and the like in the form of a wedge shaped metallic hollow body having flat outer skins brought together and I suitably connected at one edge, but separated at the other edge by a firmly joined longitudinal wall, firmly attached transverse reinforcing frame members arranged inthe direction of flight, the latter including three web bars in zigzag fashion, one of which is attached to the inside of the longitudinal wall and joined to its girders by means of rivets driven parallel to the rudder covering skin with a more remote bar attached to the web girders by means of rivets driven at one end vertically and at the other parallel to the cover skin.

joining the interna 2. An aircraft rudder of the character set forth in claim 1 wherein the diagonal bar is fastened to the girders by the same rivets driven parallel to the cover skin, which fix the cross-members to the girder.

3. An aircraft rudder and the like'of metal construction including a pair of fiat converging plates with an internal frame structure therefor including transverse girder members rigidly secured to the inner sides of the fiat plates and three web reinforcing members in zigzag fashion secured to said girders, certain of said web members being attached directly to a flat plate by the rivets through the horizontal flange of the girder and certain other web members being attached to the vertically disposed flange of the girder.

. 4. An aircraft-rudder of the character set forth in claim 3 including a bulkhead rigidly fastened to the diverging ends of the girder members and to the web reinforcing members disposedthereat, and also to the flat covering plates.

5. The method of manufacturing an aircraft rudder and the like including a pair of metallic plates and an internal reinforcing frame structure which comprises the attachment of certain of the frame members to one metallic plate and-certain of the co-functioning frame members to the other metallic plate, and then first connecting the two metallic plates together at their converging edges by internal riveting operations with the diverging edges of the metallic plates spread apart, 'and then bringing the diverging edges of the platesto their proger angular position and frame members of one plate to the internal frame members of the other.-

6. The method according to claim 5 which includes the further step of joining a bulkhead wall to the base of the rudder.

7. A metal aircraft rudder having two fiat StI'GSSGLlOlltPI skins spaced at one edge by a longitudinal wall and converging towards the outer edge, with transverse stifiening frames disposed within the rudder and each comprising two girder members rigidly fixed to the skins and a web consisting of three members arranged in zigzag fashion and joined with their ends to the girders,-one of the two cross members of the web also fixed to the inside of the base wall, said skins. wall and transverse members being rigidly connected to form a hollow box resisting bending and torsional stresses. I

8. An aircraft rudder of the character set forth in claim 7, wherein the cross member, remote from the base wall being at one end joined to the corresponding girder by a rivet or rivets perpendicular to the skin to which the girder is fixed, both the other end of said cross-member and one end of the web diagonal being joined to the other girder by a rivet which is parallel to the skin.

9. An aircraft rudder of the character set forth in claim 7, wherein the cross member remote from the base wall being one end joined to the corresponding girder by a rivet or rivets perpendicular to the skin to which the girder is fixed, both the other end of said cross-member and one end of the web diagonal being joined to the other girder by a rivet which is parallel to the skin, the ends of the cross member fixed to the box-wall and the other end of the diagonal being joined to the girders by rivets which are parallel to the skins.

In testimony whereof, I have signed my name to this specification.

" LUDWIG STAIGER. 

